You can apply both materials and textures to objects in your VRML world. Materials are easier, mean the user has to download less data (usually), and are probably quicker to render (draw to the screen). Due to these reasons, I'm only going to discuss materials here. The topic of Separators doesn't really fit with materials, but it is of such importance that it can't be left till later!

Material

The Material node defines the current default material for your world. All shapes drawn after a node are drawn using that material. Differant objects "use" materials in a differant manner. You should also bear in mind that differant browsers will give slightly different results for the same values. Both the shininess and transparency parameters are self explanitory. The 4 differant colour parameters may seem a litte confusing. If you just want a fairly standard colour, set the diffuseColor parameter, and leave the rest blank. It is possible to define more than 1 material with this node, but this isn't often neccisary or desireable.

Parameter	Default Value	Data Type
ambientColor	0.2 0.2 0.2	MColour
diffuseColor	0.8 0.8 0.8	MColour
emissiveColor	0.0 0.0 0.0	MColour
shininess	0.2	MFloat
specularColor	0.0 0.0 0.0	MColour
transparency	0.0	MFloat

Example: define a nice shiny green material.

Material {
	ambientColor 0.0 0.4 0.0
	diffuseColor 0.0 1.0 0.0
	shininess 0.7
}

MaterialBinding

Defines how a material is applied to objects. This node isn't very important, and certainly doesn't need to be used. If you specify more that one material in the Material node, then this node defines how these various materials are put onto a shape. Generally speaking, it defines how the various materials are cycled. The best way to use this is by trial and error. For a more detailed description, I recomend you use a book or other available internet material.This node has no effect when you only define a single material in a Material node statement.

Parameter	Default Value	Data Type
value	DEFAULT	Enumerated - DEFAULT | OVERALL | PER_PART | PER_PART_INDEXED | PER_FACE | PER_FACE_INDEXED | PER_VERTEX | PER_VERTEX_INDEXED

Example: Cycle the 3 primary colours over different faces of a cube.

Material {
	diffuseColor [1 0 0, 0 1 0, 0 0 1]
	ambientColor [0.3 0 0, 0 0.3 0, 0 0 0.3]
}

MaterialBinding {
	value PER_FACE
}

Cube {}

Separator

This node basically saves the current state (i.e. material, lighting, transformation etc.) when it is encountered, and restores the state once it is closed. This is a useful way to reset the transformation and rotation values. It has one parameter, but this is not in the scope of this discusion, and I have certainly never found any need to use it.
Example: place a cube at (4,4,4) and a cylinder at (-2,0,-1), with it's central axis along the x axis.

Separator {
	Translation {
		translation -2 0 -1
	}
	Rotation {
		rotation 0 0 1 1.570796
	}
	Cylinder {}
}
#-----Upon reaching the '}' above, the translation and rotation values
#-----are lost, so the axes are the 'right-way-round' again.
Separator {
	Transformation { 
		transformation 4 4 4
	}
	Cube {}
}

TransformSeparator

Similar to the Separator node, but this node only restores the transformation values upon it's termination. In other words, materials or lights inside a TransformSeparator will affect nodes appearing outside and after this node, whereas they wouldn't if they were placed inside a Separator node.
Example: the first cube in this world will appear blue, as will the next, but the last will appear red.

Material {
	diffuseColor 0 0 1
}
Cube {}

Separator {
	Material {
		diffuseColor 1 0 0
	}
}   #<<<<---"Red" material is lost here.

Cube {}

TransformSeparator {
	Material {
		diffuseColor 1 0 0
	}
}   #<<<<---This time, "red" is kept.

Cube {}

SpinGroup

A really usefull node, but one that should be used carefully. It basically spins every object inside it in an author defineable manner. It has one parameter, rotation which specifies the axis and rate of spin.

Parameter	Default Value	Data Type
rotation	(unknown)	Rotation

Example: let's spin a Colour-Cycled Cube! This is a fully valid VRML file, and you can see what it does by clicking the here.

#VRML V1.0 ascii

SpinGroup {
	rotation 1 1 -0.2 0.08
	
	DirectionalLight {}
	PerspectiveCamera {
		position 0 0 5
	}
	
	Material {
		diffuseColor [1 0 0, 0 1 0, 0 0 1]
		ambientColor [0.1 0 0, 0 0.1 0, 0 0 0.1]
		shininess [0.4, 0.4, 0.4]
	}
	MaterialBinding {
		value PER_FACE
	}

	Cube {}
}

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